duck

float speed = 2;
Vector3 target;

void SetTarget(Vector3 pos) {

    target = pos;

}

void Update() {

    // get the vector from current position to target
    Vector3 targetDelta = target - transform.position;
    Vector3 targetDirection = targetDelta.normalized;

    // calculate direction and distance to move
    float moveStepSize = speed * Time.deltaTime;

    if (moveStepSize > targetDelta.magnitude) {
        // this step would overshoot target, so just set position
        transform.position = target;
    } else {
        // step towards direction
        transform.position += targetDirection * moveStepSize;
    }

}